1. Field of Invention
The present invention relates to a real-time positioning system, in particular to a real-time positioning system applied in any open or closed spaces.
2. Related Art
In the prior art, most of the currently available wireless positioning systems are formed by combining a control device and a plurality of wireless gateways or wireless routers (wireless routers are illustrated below as an example), so as to locate a mobile device carried by a user in a valid space.
Such wireless positioning system allocates the plurality of wireless routers in a valid space, and the signal detecting ranges of neighboring wireless routers overlap partially to avoid a blind area in the detecting ranges, in which the wireless routers employ omni-directional antennas to send detecting signals. When the user equipped with the mobile device enters the valid space, a signal interconnection motion occurs with some of the wireless routers. Each wireless router analyzes the strength of the signal interconnection with the mobile device (such as received signal strength indicator (RSSI), or link quality indication (LQI)), calculates a substantial distance of the mobile device corresponding to each wireless router, and transmits the substantial distance back to the control device. The control device analyzes the location of the mobile device in the valid space according to the substantial distances and the locations of the wireless routers that transmit the substantial distances back, thereby positioning the location of the user.
However, there are other problems to be solved, i.e., when an emergency occurs or tasks with great danger are carried out such as fire, poison gas leakage, radiant ray leakage, mining, or carrying out chemical reactions utilizing chemical tanks in buildings and sites of houses, plant, company, and administration, if these buildings and sites are not allocated with the wireless positioning systems in advance, the rescue personnel can merely determine the rescuing and escaping paths by themselves according to blueprints of the sites, or the memory of the passed passages, thereby making the rescuing and escaping tasks more difficult.